Bay-fronted suburban semis with hipped roofs and side passages. Dominant outer-London stock.
1930s semi-detached stock in Westminster responds best to extensions that respect the existing rhythm. For Victorian and Edwardian period property, side returns and rear infill are routine. For 1930s suburban, single-storey rear and loft conversions dominate. We design to the block, not the brochure.
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Every Westminster postcode district we draw in, the stock that dominates it and the authority that validates a 1930s semi project there. Westminster fees below are the statutory England rates for 2026, not 1930s semi project estimates.
| Postcode | Area | Dominant stock | What it means for a 1930s semi project |
|---|---|---|---|
| SW1H | St James's Park | Grand Georgian and Regency terraces in Belgravia and Pimlico; Victorian and Edwardian mansion blocks; heritage-rich townhouses throughout; very high listed building density | SW1H covers St James's Park only; Westminster City Council handles the 1930s semi project, and St James's Park case officers apply the SW1H conservation-area map. |
| SW1P | Westminster / Vincent Square | Grand Georgian and Regency terraces in Belgravia and Pimlico; Victorian and Edwardian mansion blocks; heritage-rich townhouses throughout; very high listed building density | Westminster / Vincent Square sits wholly inside SW1P, so Westminster City Council validates every 1930s semi project submitted from an SW1P address. |
| SW1V | Pimlico | Regency terraces, post-war estates | A 1930s semi project at an SW1V address in Pimlico is determined by Westminster City Council under its own Local Plan policies for Pimlico. |
| SW1W | Belgravia / Victoria | Regency stucco terraces, listed buildings | SW1W covers Belgravia / Victoria only; Westminster City Council handles the 1930s semi project, and Belgravia / Victoria case officers apply the SW1W conservation-area map. |
| SW1X | Knightsbridge / Belgravia | Regency stucco terraces, listed buildings | Knightsbridge / Belgravia is split at SW1X. Either Westminster City Council or RBKC Planning can determine a 1930s semi project here, so the SW1X address is checked against both policies maps first. |
| SW1Y | St James's | Grand Georgian and Regency terraces in Belgravia and Pimlico; Victorian and Edwardian mansion blocks; heritage-rich townhouses throughout; very high listed building density | St James's sits wholly inside SW1Y, so Westminster City Council validates every 1930s semi project submitted from an SW1Y address. |
| W1B | Regent Street | Grand Georgian and Regency terraces in Belgravia and Pimlico; Victorian and Edwardian mansion blocks; heritage-rich townhouses throughout; very high listed building density | W1B covers Regent Street only; Westminster City Council handles the 1930s semi project, and Regent Street case officers apply the W1B conservation-area map. |
| W1D | Soho | Georgian terraces, mixed-use | Soho sits wholly inside W1D, so Westminster City Council validates every 1930s semi project submitted from an W1D address. |
Roof pitch, wall build-up and plot depth change every few Westminster streets, and each one changes what a 1930s semi project can achieve at that address.
Westminster conservation designations: there are 56 across Westminster City Council, Pimlico, Soho, Covent Garden among them. Designation costs a Westminster owner the permitted-development route: a 1930s semi project then needs a £258 householder application over 8 weeks, in place of the £120 prior approval route that takes 6 weeks. Covent Garden is the Westminster designation that most often changes a 1930s semi project design.
Westminster and Article 4: Multiple Article 4 Directions — office-to-residential restrictions, HMO conversions, retail to residential in shopping zones. A 1930s semi project planned at a NW8 address is checked against that direction first; Westminster City Council publishes the Westminster extent, and the NW8 line rarely follows the Westminster boundary you would expect.
Digging below a Westminster property: Westminster basement policy restricts to single-storey, typically under 50% of rear garden footprint; lightwells and rooflights strictly controlled in conservation areas. Where a 1930s semi project in Westminster involves excavation that is read beside the Party Wall etc. Act 1996, which needs two months notice for a Westminster dig within 3 m of a neighbour, and Westminster City Council expects the NW8 ground conditions addressed in the application.
Westminster housing stock: Grand Georgian and Regency terraces in Belgravia and Pimlico; Victorian and Edwardian mansion blocks; heritage-rich townhouses throughout; very high listed building density. Heritage-first planning approach; listed buildings on almost every street; basement and rear extension policies particularly strict. Read that before choosing a 1930s semi project route in Westminster — construction, not postcode, sets what is achievable. 1930s semi projects in Westminster start at £840 on a fixed fee, or £1,750 for the Complete package covering both Westminster City Council submissions.
Sources for this Westminster 1930s semi project page: borough policies maps and conservation-area registers (2025–26), Royal Mail postcode district boundaries, the Town and Country Planning (Fees for Applications) (England) Regulations, the Town and Country Planning (General Permitted Development) (England) Order 2015 as amended, and the Party Wall etc. Act 1996.